The Sword of the Silver Knight (Boxcar Children #103)

The Aldens are volunteers at a medieval fair! They are excited to wear costumes and entertain the crowds. But when a valuable sword goes missing, the children know their toughest job is going to be catching the thief.

Long Synopsis:

The Aldens are volunteers at a medieval fair! They are excited to wear costumes and entertain the crowds. But when a valuable sword goes missing, the children know their toughest job is going to be catching the thief.